How to execute a @Scheduled method in java Spring immediately and then according to cron?

Question

I've got a method:

@Scheduled(cron="0 */5 * * * *")
public void syncRoutine() { }

So it runs every 5 minutes.

Is it possible to schedule a method to run immediately first time and then according to cron?

Answer 1

You can combine multiple @Scheduled annotations with @Schedules annotation:

@Schedules(value = {
        @Scheduled(initialDelay = 15_000,
                fixedDelay = Long.MAX_VALUE),
        @Scheduled(cron = "0 */5 * * * *")
})
public void scheduleFixedDelayTask() {
    System.out.println("Fixed delay task - " +
            System.currentTimeMillis() / 1000);
}

The task will be executed the first time after the initialDelay (at 15 sec.) value. We make it impossible to repeat with fixedDelay = Long.MAX_VALUE because let cron do it.

OR

You can use @PostConstruct and @Scheduled annotation together:

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;

@Component
public class ScheduleClass {

    @PostConstruct
    public void onStartup() {
        scheduleFixedDelayTask();
    }

    @Scheduled(cron = "0 */1 * * * *")
    public void scheduleFixedDelayTask() {
        System.out.println("Fixed delay task - " +
                System.currentTimeMillis() / 1000);
    }
}

Normally you don't need to add cron for a task that will run every 5 minutes but I'm assuming this is an example.